Design Lesson #7: Present the user only with unambiguous and useful options

Hidden and confusing software controls perplex users and waste their time.

Karl Wiegers

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A photo of a confused-looking man.
Shrug photo created by wayhomestudio — www.freepik.com

I belong to a small gaming group. At a recent game night, my friend Rik decided to use the clock app on his phone as a 30-second countdown timer. After the alarm sounded when the timer reached zero, it then took Rik another 30 seconds to deduce how to turn off the alarm sound, which was to press the phone’s Home button. Rik is an extremely bright software engineer with nearly 50 years of computer experience. Yet, the mechanism to turn off the alarm sound wasn’t apparent to him, nor to any of us in the group of technical people. It’s easy to do once you know about it. Obvious? Not so much.

Figure 1 shows the timer screen when it’s counting down. Buttons to cancel the timer and to pause the countdown are clearly visible. Buttons like these are signifiers, indicators that let users discover how to perform an action with a product. Clear signifiers are essential when text labels like these are not available, but sometimes even the text isn’t clear. Fortunately, this initial display is easy and obvious to use.

A screen shot of a smartphone’s timer app while the timer is counting down.
Figure 1. This is the phone screen when the countdown timer is running.

Figure 2 shows the app screen when the countdown is over. This design lacks any clue about how to turn off the timer’s alarm sound. The Cancel button doesn’t do it, although that seems like a reasonable guess. In fact, Cancel doesn’t do anything at that point, so why is it even visible? The green Start button catches the eye, but that one doesn’t seem right. Tapping Start actually restarts the timer without silencing the first alarm, which then turns itself off when the second timing cycle is complete. This makes no sense at all to me. A misleading signifier is even more confusing than having no signifier at all.

A screenshot of a smartphone’s timer app after the countdown is completed.
Figure 2. How to turn off the sound when the timer countdown ends is not obvious.

Our experience attempting to use this timer app yielded a valuable design insight:

Design Lesson #7: Present the user only with

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Karl Wiegers

Author of 14 books, mostly on software. PhD in organic chemistry. Guitars, wine, and military history fill the voids. karlwiegers.com and processimpact.com